1. Field of the Invention
The present invention pertains to a method for the marking of information elements or particulars on a connector of a card known as an electronic chip card, said connector having metal contacts with a given thickness.
The invention can be applied in a particularly advantageous way to the marking of electronic chip cards such as bank cards or telephone cards for example, inter alia for the recording thereon of a security message or a manufacturer's identification.
In general, chip cards comprise micromodules that take the form of a supporting strip made of epoxy resin bearing, on one face, the electronic component (the chip) properly speaking and, on another face, an electrical connector constituted by metal contacts that are most usually made of copper, covered with a layer of nickel and a layer of gold. The micromodules are housed in cavities prepared in the thickness of the card, so as to leave said metal contacts accessible from the exterior.
2. Description of the Prior Art
At present, the micromodules bear no particulars of any kind whatsoever. Only the manufacturer's corporate name sometimes appears on the card itself. Especially as regards to security, the total absence of identification allows the possibility of interchanging the micromodule and the body of the card.
A certain number of methods could be envisaged in order to carry out the marking of particulars on a micromodule and, more specifically, on the connector of said micromodule.
Marking by printing for example would consist in depositing layers of ink on the metal elements of the connector. However, this method would raise two problems, i.e. firstly, a problem of electrical contacts getting deteriorated because the inks are generally not conductive and, secondly, a problem of a certain degree of sensitivity to wear and tear on the part of the embossed etchings.
Mechanical etching would be incompatible with an already assembled micromodule because of the brittleness of the chip. Besides, it is almost impossible to conceive of an industrial-scale solution for this application.
Photoetching by chemical means does not enable the etching to be controlled in depth and it is imperative that the coating of the metal contacts should not be penetrated too deeply.
Stamping, for its part, is not a process that can be carried out at any time whatsoever during the manufacturing process, which means that this technology has little flexibility.
Hence, the technical problem to be resolved by the object of the present invention is that of proposing a method for the marking of information elements or particulars on a connector of a card known as an electronic chip card, said connector having metal contacts of a given thickness, said method making it possible to obtain a lasting marking, without deterioration in the course of time, that would introduce no disturbance into the electrical contact and would not injure the electronic chip itself while at the same time retaining a high degree of flexibility, notably as regards the place of the marking operation in the card manufacturing cycle.